David Harrington enjoys a love/hate relationship with his main musical compatriot.

"In a certain way, you have to be crazy to be a violinist," says Harrington, founder of Kronos Quartet.

"I probably wouldn't play the violin if I weren't in Kronos. It's too much work. And the violin always wins. It's a taskmaster of immense dimension."

Yet Harrington believes there's a comforting and almost primal quality about the instrument that continues to appeal to him.

"I love the fact it's made out of wood. In the earliest days the strings were made out of animal intestines. I love the fact it takes pine resin to stick to the horse hair to cause the tone. I love the fact that it's the skin of your fingers that depresses the strings," he says.

Now in his 37th year with Kronos Quartet, Harrington remains equally enamored with classical music and all its latent innovations. Kronos has proven to be a fearless force in expanding the boundaries of the string quartet. For Harrington, the phrase "string quartet" can personally apply to anything that involves strings. During the group's performance today in Lawrence, he'll be introducing a one-stringed Serbian instrument called a gusle.

Harrington learned to play it by watching YouTube.

"Basically, every concert we do is different," he says during a tour stop in Michigan.

"We'll be bringing our audience in Lawrence into some of the work we've done with Terry Riley for the past 30 years. A piece by Aleksandra Vrebalov ("... hold me, neighbor, in this storm ...") might be the most multimedia that we're doing that evening. It involves quite a few different instruments. This piece allows us to morph into almost different musicians for a while, and I love that."

Among the highlights of the Lawrence appearance will be an excerpt from Riley's "Sun Rings," which the famed minimalist composer wrote for Kronos. The multimedia opus was commissioned by NASA, and it features actual celestial sounds recorded by the agency.

Kronos will perform the concluding movement of "Sun Rings," which was inspired when the composer heard poet Alice Walker chanting the phrase "One earth, one people, one love" during a radio appearance on Sept. 12, 2001.

Harrington says, "Really, it brought the piece back to earth rather than sending it out to the cosmos."

'Alive and vibrant'

"The Kronos Quartet has by now attained a kind of legendary status that far surpasses the groundbreaking radicalism of their younger days," says Kip Haaheim, associate professor of music theory and music composition at Kansas University.

"What strikes me about them 'live' is that they have a great blend between technical brilliance and a quality that I would call 'feel.' They make the music feel alive and vibrant in a way that goes way beyond playing the notes and rhythms properly. There is a kind of depth and authority about what they do that compels the listener to relax and enjoy the journey."

The Grammy-winning act has shared stages with artists ranging from poet Allen Ginsberg to singers David Bowie and Tom Waits. It's appeared on recordings by the likes of Nine Inch Nails, DJ Spooky, Nelly Furtado and Dave Matthews.

As such, the San Francisco unit is often regarded as being among the most cutting-edge of the contemporary classical groups.

"I've never been concerned about cutting any edges," Harrington says. "What I like to do is bring things into the world of our group that I've never been a part of before. I like to challenge composers whose work seems really interesting to me. To make something they've never made before. ... If that's cutting edge, then that's cool with me."

Harrington - who joins fellow violinist John Sherba, violist Hank Dutt and cellist Jeffrey Zeigler in Kronos - claims he's on the phone with 30 to 40 different composers each week. Since forming in 1973, Kronos boasts nearly 700 pieces written specifically for the quartet.

"That body of work is something I want to continue to grow and continue to reimagine all the time. ... I'm more concerned about what's next than what we've done previously," Harrington says.

Creative triggers

In typical fashion, Kronos Quartet finds itself in the midst of a packed month of live dates, which began in New York and concludes in Spain.

"You get weary from the travel. And it's hard to sleep sometimes. But we get so much energy from the music we play and the people we meet," says the 60-year-old violinist. (He fondly recalls a bygone Lawrence gig because the band got to meet the late composer and critic Virgil Thomson.)

Harrington admits his group is "having a great time exploring." From the roster of upcoming projects, it's unlikely his ensemble will have much trouble keeping things interesting.

"I've got a great idea for the future," Harrington reveals. "I'd like to go out onstage and have Kronos trigger samples of various things Noam Chomsky has said over the years. There might not be any instrumental sound. It might be all Chomsky. I had a great conversation with him the other day, and I'm really inspired to do that."